1. Field of the Invention
This invention relates to a blow-molded structure having an integrally molded, coextruded living hinge and method of making the same.
2. Background Art
Vehicle panels, such as flipper panels, are commonly manufactured using a blow-molded machine. Blow-molding panels provide significant advantages over other manufacturing processes such as injection molding. For example, blow-molded parts are stronger, less expensive to manufacture, easier to design, and usually offer weight savings.
Some panels, such as seat flipper panels, carry significant loads and therefore must be manufactured out of a plastic material that has sufficient structural rigidity and strength. Typically, the panels are made out of a glass- or mineral-filled polymer. In particular, the panels are made out of a glass-filled polypropylene material.
However, some panels, such as vehicle flipper panels, are also subject to repeated cyclic loading. Although the flipper panels are generally manufactured out of a glass-filled, polypropylene material that is rigid and provides sufficient structural qualities, the repeated cyclic loading of the panel causes the glass-filled polypropylene material to fracture resulting in a part that can no perform to the original specification.
Accordingly, manufacturers of flipper panels have resorted to using a subsequent manufacturing step wherein a portion of the flipper panel is modified and a metal hinge is attached thereto. This extra step adds time and money, and creates manufacturing difficulties.
Accordingly, there exists a need for a cost effective and easily manufactured blow-molded structure having a structurally rigid, load bearing portion and a flexible portion to perform product specified cyclic functions.